PSE device and powered device of optical power supply system, and optical power supply system

ABSTRACT

An optical power supply system includes a first data communication device and a second data communication device. The first data communication device includes a power sourcing equipment device including a first semiconductor laser; and a first transmitter including a second semiconductor laser and a first modulator. The second data communication device includes a powered device comprising a photoelectric conversion element; a receiver; a data processing unit; and a second transmitter including a third semiconductor laser and a second modulator. The first data communication device and the second data communication device perform optical communication with each other. The electric power obtained by the conversion of the feed light by the photoelectric conversion element is driving power for the second transmitter and the receiver.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/944,068 filed on Jul. 30, 2020, which is a divisional ofU.S. patent application Ser. No. 16/870,826 filed on May 8, 2020, and isbased upon and claims the benefit of priority from the prior JapanesePatent Application No. 2019-097548, filed on May 24, 2019, the entirecontents of which are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to optical power supply.

Description of Related Art

Recently, there has been studied an optical power supply system thatconverts electric power into light called feed light, transmits the feedlight, converts the feed light into electric energy, and uses theelectric energy as electric power.

There is disclosed in JP 2010-135989 A an optical communication devicethat includes: an optical transmitter that transmits signal lightmodulated with an electric signal and feed light for supplying electricpower; an optical fiber including a core that transmits the signallight, a first cladding that is formed around the core, has a refractiveindex lower than that of the core, and transmits the feed light, and asecond cladding that is formed around the first cladding, and has arefractive index lower than that of the first cladding; and an opticalreceiver that operates with electric power obtained by converting thefeed light transmitted through the first cladding of the optical fiber,and converts the signal light transmitted through the core of theoptical fiber into the electric signal.

SUMMARY

In optical power supply, further improvement of optical power supplyefficiency is required. For that, for example, improvement ofphotoelectric conversion efficiency at the power supplying side and thepower receiving side is required.

According to a first aspect of the present disclosure, there is provideda power sourcing equipment (PSE) device of an optical power supplysystem, including a semiconductor laser that oscillates with electricpower, thereby outputting feed light, and includes a semiconductorregion exhibiting a light-electricity conversion effect, wherein asemiconductor material of the semiconductor region is a laser mediumhaving a laser wavelength of 500 nm or less.

According to a second aspect of the present disclosure, there isprovided an optical power supply system including:

-   -   the above PSE device; and    -   a powered device including a photoelectric conversion element        that converts the feed light output by the PSE device into        electric power.

According to a third aspect of the present disclosure, there is provideda powered device of an optical power supply system, including aphotoelectric conversion element that converts feed light into electricpower, and includes a semiconductor region exhibiting alight-electricity conversion effect,

-   -   wherein a semiconductor material of the semiconductor region is        a laser medium having a laser wavelength of 500 nm or less.

According to a fourth aspect of the present disclosure, there isprovided an optical power supply system including:

-   -   a power sourcing equipment (PSE) device including a        semiconductor laser that oscillates with electric power, thereby        outputting feed light; and    -   the above powered device,    -   wherein the feed light is input to the powered device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are not intended as a definition of the limitsof the invention but illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention, wherein:

FIG. 1 is a block diagram of a power over fiber system according to afirst embodiment of the present disclosure;

FIG. 2 is a block diagram of a power over fiber system according to asecond embodiment of the present disclosure;

FIG. 3 is a block diagram of the power over fiber system according tothe second embodiment of the present disclosure and shows opticalconnectors and so forth; and

FIG. 4 is a block diagram of a power over fiber system according toanother embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, one or more embodiments of the present disclosure will bedescribed with reference to the drawings. However, the scope of thepresent invention is not limited to the disclosed embodiments orillustrated examples.

First Embodiment

As shown in FIG. 1 , a power over fiber (PoF) system 1A (optical powersupply system) of this embodiment includes a power sourcing equipment(PSE) device 110, an optical fiber cable 200A and a powered device (PD)310.

In the present disclosure, a PSE device converts electric power intooptical energy and supplies (sources) the optical energy, and a powereddevice receives (draws) the supplied optical energy and converts theoptical energy into electric power.

The PSE device 110 includes a semiconductor laser 111 for power supply.

The optical fiber cable 200A includes an optical fiber 250A that forms atransmission path of feed light.

The powered device 310 includes a photoelectric conversion element 311.

The PSE device 110 is connected to a power source, and electricallydrives the semiconductor laser 111 and so forth.

The semiconductor laser 111 oscillates with the electric power from thepower source, thereby outputting feed light 112.

The optical fiber cable 200A has one end 201A (first end) connectable tothe PSE device 110 and the other end 202A (second end) connectable tothe powered device 310 to transmit the feed light 112.

The feed light 112 from the PSE device 110 is input to the one end 201Aof the optical fiber cable 200A, propagates through the optical fiber250A, and is output from the other end 202A of the optical fiber cable200A to the powered device 310.

The photoelectric conversion element 311 converts the feed light 112transmitted through the optical fiber cable 200A into electric power.The electric power obtained by the conversion of the feed light 112 bythe photoelectric conversion element 311 is driving power needed in thepowered device 310. The powered device 310 is capable of outputting, foran external device(s), the electric power obtained by the conversion ofthe feed light 112 by the photoelectric conversion element 311.

Semiconductor materials of semiconductor regions of the semiconductorlaser 111 and the photoelectric conversion element 311 aresemiconductors having a laser wavelength being a short wavelength of 500nm or less. The semiconductor regions exhibit light-electricityconversion effect.

Semiconductors having a laser wavelength being a short wavelength have alarge band gap and a high photoelectric conversion efficiency, and henceimprove photoelectric conversion efficiency at the power supplying side(PSE side) and the power receiving side (PD side) in optical powersupply, and improve optical power supply efficiency.

Hence, as the semiconductor materials, laser media having a laserwavelength (base wave) of 200 nm to 500 nm may be used. Examples thereofinclude diamond, gallium oxide, aluminum nitride and gallium nitride.

Further, as the semiconductor materials, semiconductors having a bandgap of 2.4 eV or greater are used.

For example, laser media having a band gap of 2.4 eV to 6.2 eV may beused. Examples thereof include diamond, gallium oxide, aluminum nitrideand gallium nitride.

Laser light having a longer wavelength tends to have a highertransmission efficiency, whereas laser light having a shorter wavelengthtends to have a higher photoelectric conversion efficiency. Hence, whenlaser light is transmitted for a long distance, laser media having alaser wavelength (base wave) of greater than 500 nm may be used, whereaswhen the photoelectric conversion efficiency is given priority, lasermedia having a laser wavelength (base wave) of less than 200 nm may beused.

Any of these semiconductor materials may be used in one of thesemiconductor laser 111 and the photoelectric conversion element 311.This improves the photoelectric conversion efficiency at either the PSEside or the PD side, and improves the optical power supply efficiency.

Second Embodiment

As shown in FIG. 2 , a power over fiber (PoF) system 1 of thisembodiment includes a power supply system through an optical fiber andan optical communication system therethrough, and includes: a first datacommunication device 100 including a power sourcing equipment (PSE)device 110; an optical fiber cable 200; and a second data communicationdevice 300 including a powered device (PD) 310.

The PSE device 110 includes a semiconductor laser 111 for power supply.The first data communication device 100 includes, in addition to the PSEdevice 110, a transmitter 120 and a receiver 130 for data communication.The first data communication device 100 corresponds to a data terminalequipment (DTE) device, a repeater or the like. The transmitter 120includes a semiconductor laser 121 for signals and a modulator 122. Thereceiver 130 includes a photodiode 131 for signals.

The optical fiber cable 200 includes an optical fiber 250 including: acore 210 that forms a transmission path of signal light; and a cladding220 that is arranged so as to surround the core 210 and forms atransmission path of feed light.

The powered device 310 includes a photoelectric conversion element 311.The second data communication device 300 includes, in addition to thepowered device 310, a transmitter 320 and a receiver 330 for datacommunication, and a data processing unit 340. The second datacommunication device 300 corresponds to a power end station or the like.The transmitter 320 includes a semiconductor laser 321 for signals and amodulator 322. The receiver 330 includes a photodiode 331 for signals.The data processing unit 340 processes received signals. The second datacommunication device 300 is a node in a communication network. Thesecond data communication device 300 may be a node that communicateswith another node.

The first data communication device 100 is connected to a power source,and electrically drives the semiconductor laser 111, the semiconductorlaser 121, the modulator 122, the photodiode 131 and so forth. The firstdata communication device 100 is a node in a communication network. Thefirst data communication device 100 may be a node that communicates withanother node.

The semiconductor laser 111 oscillates with the electric power from thepower source, thereby outputting feed light 112.

The photoelectric conversion element 311 converts the feed light 112transmitted through the optical fiber cable 200 into electric power. Theelectric power obtained by the conversion of the feed light 112 by thephotoelectric conversion element 311 is driving power needed in thesecond data communication device 300, for example, driving power for thetransmitter 320, the receiver 330 and the data processing unit 340. Thesecond data communication device 300 may be capable of outputting, foran external device(s), the electric power obtained by the conversion ofthe feed light 112 by the photoelectric conversion element 311.

The modulator 122 of the transmitter 120 modulates laser light 123output by the semiconductor laser 121 to signal light 125 on the basisof transmission data 124, and outputs the signal light 125.

The photodiode 331 of the receiver 330 demodulates the signal light 125transmitted through the optical fiber cable 200 to an electric signal,and outputs the electric signal to the data processing unit 340. Thedata processing unit 340 transmits data of the electric signal to anode, and also receives data from the node and outputs the data to themodulator 322 as transmission data 324.

The modulator 322 of the transmitter 320 modulates laser light 323output by the semiconductor laser 321 to signal light 325 on the basisof the transmission data 324, and outputs the signal light 325.

The photodiode 131 of the receiver 130 demodulates the signal light 325transmitted through the optical fiber cable 200 to an electric signal,and outputs the electric signal. Data of the electric signal istransmitted to a node, whereas data from the node is the transmissiondata 124.

The feed light 112 and the signal light 125 from the first datacommunication device 100 are input to one end 201 (first end) of theoptical fiber cable 200, propagate through the cladding 220 and the core210, respectively, and are output from the other end 202 (second end) ofthe optical fiber cable 200 to the second data communication device 300.

The signal light 325 from the second data communication device 300 isinput to the other end 202 of the optical fiber cable 200, propagatesthrough the core 210, and is output from the one end 201 of the opticalfiber cable 200 to the first data communication device 100.

As shown in FIG. 3 , the first data communication device 100 includes alight input/output part 140 and an optical connector 141 attached to thelight input/output part 140, and the second data communication device300 includes a light input/output part 350 and an optical connector 351attached to the light input/output part 350. An optical connector 230provided at the one end 201 of the optical fiber cable 200 is connectedto the optical connector 141, and an optical connector 240 provided atthe other end 202 of the optical fiber cable 200 is connected to theoptical connector 351. The light input/output part 140 guides the feedlight 112 to the cladding 220, guides the signal light 125 to the core210, and guides the signal light 325 to the receiver 130. The lightinput/output part 350 guides the feed light 112 to the powered device310, guides the signal light 125 to the receiver 330, and guides thesignal light 325 to the core 210.

As described above, the optical fiber cable 200 has the one end 201connectable to the first data communication device 100 and the other end202 connectable to the second data communication device 300 to transmitthe feed light 112. In this embodiment, the optical fiber cable 200transmits the signal light 125/325 bidirectionally.

As the semiconductor materials of the semiconductor regions, whichexhibit the light-electricity conversion effect, of the semiconductorlaser 111 and the photoelectric conversion element 311, any of thosedescribed in the first embodiment can be used, thereby achieving a highoptical power supply efficiency.

Although some embodiments of the present disclosure have been describedabove, these embodiments are made for purposes of illustration andexample only. The present invention can be carried out in various otherforms, and each component may be omitted, replaced or modified withoutdeparting from the scope of the present invention.

For example, like an optical fiber cable 200B of a power over fibersystem 1B shown in FIG. 4 , an optical fiber 260 that transmits signallight and an optical fiber 270 that transmits feed light may be providedseparately. Further, the optical fiber cable 200B may be composed of aplurality of optical fiber cables.

Although power over fiber systems have been described, the presentdisclosure is applicable to optical power supply in general.

In an optical power supply system according to at least one embodimentof the present disclosure, a PSE device includes a semiconductor laserthat oscillates with electric power, thereby outputting feed light, andincludes a semiconductor region exhibiting the light-electricityconversion effect, wherein a semiconductor material of the semiconductorregion is a laser medium having a laser wavelength of 500 nm or less.

In at least one embodiment, the semiconductor material is the lasermedium having a band gap of 2.4 eV or greater.

In at least one embodiment, the semiconductor material is one selectedfrom diamond, gallium oxide, aluminum nitride and gallium nitride.

In an optical power supply system according to at least one embodimentof the present disclosure, a powered device includes a photoelectricconversion element that converts feed light into electric power, andincludes a semiconductor region exhibiting the light-electricityconversion effect, wherein a semiconductor material of the semiconductorregion is a laser medium having a laser wavelength of 500 nm or less.

In at least one embodiment, the semiconductor material is the lasermedium having a band gap of 2.4 eV or greater.

In at least one embodiment, the semiconductor material is one selectedfrom diamond, gallium oxide, aluminum nitride and gallium nitride.

According to an optical power supply system according to at least oneembodiment of the present disclosure, a semiconductor material(s) havinga high photoelectric conversion efficiency improves the photoelectricconversion efficiency at the power supplying side (PSE side) and/or thepower receiving side (PD side) in optical power supply, and improves theoptical power supply efficiency.

What is claimed is:
 1. An optical power supply system comprising: afirst data communication device including a power sourcing equipment(PSE) device, the PSE device including a first semiconductor laserconfigured to oscillate with electric power, and output feed light, anda first transmitter including a second semiconductor laser configured tooutput first laser light, and a first modulator configured to modulatethe first laser light and output first signal light; and a second datacommunication device including a powered device comprising aphotoelectric conversion element configured to convert the feed lightinto the electric power, the photoelectric conversion element includinga semiconductor region exhibiting a light-electricity conversion effect,a receiver configured to demodulate the first signal light to anelectric signal, and output the electric signal, a data processing unitconfigured to receive the electric signal and output data based on theelectric signal, and a second transmitter including a thirdsemiconductor laser configured to output second laser light, and asecond modulator configured to modulate the second laser light to asecond signal light based on the data, and output the second signallight to the first data communication device, wherein the first datacommunication device and the second data communication device performoptical communication with each other, and the electric power obtainedby the conversion of the feed light by the photoelectric conversionelement is driving power for the second transmitter and the receiver. 2.The optical power supply system according to claim 1, wherein asemiconductor material of the semiconductor region is a laser mediumhaving a band gap of 2.4 eV or greater.
 3. The optical power supplysystem according to claim 1, wherein a semiconductor material of thesemiconductor region is diamond.
 4. The optical power supply systemaccording to claim 1, wherein a semiconductor material of thesemiconductor region is gallium oxide.
 5. The optical power supplysystem according to claim 1, wherein a semiconductor material of thesemiconductor region is aluminum nitride.
 6. The optical power supplysystem according to claim 1, wherein a semiconductor material of thesemiconductor region is gallium nitride.
 7. The optical power supplysystem according to claim 1, further comprising an optical fiber cablethat includes a first end connectable to the PSE device and a second endconnectable to the powered device to transmit the feed light.
 8. Theoptical power supply system according to claim 1, further comprising anoptical fiber cable that includes a first end connectable to the firstdata communication device and a second end connectable to the seconddata communication device to transmit the feed light, the first signallight, and the second signal light.
 9. The optical power supply systemaccording to claim 1, further comprising a first optical fiber cableconnecting the first data communication device and the second datacommunication device to transmit the feed light, and a second opticalfiber cable connecting the first data communication device and thesecond data communication device to transmit the first and second signallights.
 10. The optical power supply system according to claim 1,wherein the first data communication device further comprises anotherreceiver configured to receive and demodulate the second signal light toanother electric signal.